1. Field of the Invention
The present invention relates to a tube-type container that comprises synthetic resin having elasticity restoring strength and that stores a fluid inside it.
2. Description of the Related Art
Regarding this kind of tube-shaped containers, replacing conventional tubes comprising a metal or aluminum foil laminated material, tubes having composition of solely synthetic resin or a synthetic resin and aluminum laminated material (in this specification, these are generically named “made of synthetic resins”) have been used in recent years.
Because such synthetic resin tube has elasticity-restoring strength, if applying a pressure to the tube and then releasing the pressure applied after discharging a fluid stored inside it, there is a problem that the elasticity-restoring strength of the tube causes the air to flow backward to the fluid-storing portion from the opening portion for discharging the fluid. As a result, the quality of the fluid stored deteriorates.
For this reason, a tube-type container, which has a flat-plate-shaped valve body attached in the opening portion for discharging a fluid so that the opening portion is blocked off by this valve body when the elasticity of the tube is restored, was proposed (e.g., Japanese Patent Laid-open No.1995-112749, Japanese Patent Laid-open No.1998-157751, Utility Model Patent Laid-open No.1984-26748).